NAD Masters M50.2 Digital Music Player & Aurender A10 Music Server

Notes on a Year Spent Streaming

Equipment report
Digital-to-analog converters,
Music servers and computer audio
NAD Masters M50.2 Digital Music Player & Aurender A10 Music Server

Then there is the matter of MQA, about which NAD is a bit misleading: “All Bluesound Players include a powerful decoder and audio renderer for the MQA system,” proclaims the promotional literature. This is true in the sense that the BluOS accepts and can partially decode files that are MQA encoded. But MQA is an end-to-end process, which means that it is an end-to-end operation that first encodes the file, unfolds it in a higher resolution, and then completes the final rendering and conversion to analog at the other end. The 50.2 does not, as it were, perform the last act (i.e., the rendering), only the first “Core” unfolding, which Stidsen tells me MQA’s Bob Stuart tells him provides about “eighty percent” of the benefit. Fair enough, but know that you will not get all the putative benefits of the format unless the fully encoded file is processed through an MQA-equipped DAC. For example, in my setup, using the 50.2 I am able to hear only the unfolded MQA file because the DACs in the Marantz, McIntosh, and Benchmarks lack any MQA capability. The only way I am able to hear a completely MQA’d file is via the Aurender A10.

So what do you do if you find the 50.2 an attractive proposition and still want full MQA? Easy enough, just pair it with one of the MQA DACs that are now beginning to proliferate the market. This is possible because the 50.2 can pass a fully encoded MQA file to a suitably equipped DAC but only when programed to do so through the BluOS app: navigate to “Settings,” then to “Player,” next to “Audio,” where you scroll down to “MQA external DAC” and turn it on. That said, it’s important to add that if you aren’t using a fully MQA-equipped DAC, then leave this setting off—otherwise the 50.2 won’t even give you the first unfolding. 

How important MQA is I cannot determine for you. It continues to be highly controversial, a debate I’m not about to engage here. Some very heavy hitters on audio for whom I have the highest regard remain unpersuaded by, even actively hostile toward it, while others, for whom I also have the highest regard, express an enthusiasm that knows few restraints. Among this latter group are TAS’s editor Robert Harley, who has written with great eloquence and, what is more important, specificity about the format’s sonic improvements. My good friend Peter McGrath, as exacting as anyone in the business, more so than most, when it comes to his own recordings (some of the finest I know), told me not long ago that his recordings sound far better when MQA’d than when listened to directly as high resolution original master files: “I consider it one of the most significant developments in audio since the beginning of digital. It transforms any PCM digital recording that I have made regardless of its original format into reproduction of almost incalculably greater resolution and beauty of sound” (though he cautions that “it will not make a poor recording good, but it will unlock all the goodness in good recordings”). 

Suffice it to say that in my still limited experience with the new medium, despite criticisms of relatively high distortion and charges that the format is lossy, I’ve never heard any evidence for these criticisms through listening, nor have I heard MQA worsen the sound of any source. At the same, its degree of improvement, as heard via Tidal through the Aurender A10 (my only experience of MQA), has ranged from modest to quite extraordinary, particularly in the areas of perceived clarity, dynamic range, air and atmosphere, and resolution (compare the wonderful Pappano version of Verdi’s Aida on Tidal Master to the compact disc). With its first unfolding, the 50.2 will readily reveal these improvements where they exist, but not so clearly as the A10 with its soup-to-nuts MQA processing.

So if DSD is not something you’re interested in, the M50.2 gets an enthusiastic recommendation from me, combining high performance, ease of use, convenience, and upgradability in a beautifully styled package. And one thing more in case it isn’t clear: If at the same time you’re shopping for a music server you’ve also been thinking of replacing a long-in-the-tooth CD player, the 50.2 obviates the need for the latter. Its player/ripper and any partnering DAC together with the BluOS app will perform the rest of the functions necessary to play your compact discs. 

Aurender A10 Cache Music Server
If Aurender had drawn up a dock brief of the kind of audiophile for whom the A10 is intended, it could easily have been with me personally in mind. Conceptually it has much in common with the NAD. Both integrate three components into one chassis, Aurender substituting DAC for burner and 4TB of storage in unmirrored configuration. (The A10 also has volume control, with remote handset, which means it can serve as the preamplifier for your whole system, though I didn’t evaluate it that way because I have too many sources to dispense with a full-function preamplifier.) As with the NAD, the brain of the A10 resides in the software: Aurender’s acclaimed Conductor App, which, like BluOs, easily integrates all the most popular streaming services, as well as Internet radio. You can also transfer ripped CDs and downloads into the A10 storage, and Conductor will organize and make readily accessible your entire library. 

The A10 has two big advantages over the NAD when it comes to streaming and hi-res downloads. First, as already noted, it does full MQA decoding. Second, it does DSD up to 128, though it won’t accept DSD 256 and 512, a limitation it shares with a considerable number of DACs that offer DSD capability. Relative to which, bear in mind that not all DACs are created equal. Some of the economy and moderately priced ones that claim 256 and 512 often wind up pushing the processing so hard you might find that 128 through the A10 or comparable units sounds better than the higher doublings through a competing but lesser DAC. Moreover, when it comes to 512, very little is available and what’s there is very expensive with humongous file sizes. Selection is greater for 256, but, again, these downloads are also pricey with comparatively large files vis-à-vis the PCM alternatives, while their sonic superiority over 128, though real, even at times substantial, is not what I would call life-changing. As usual, if you can manage to do some auditioning before purchasing, you should.

Getting the A10 to connect to my setup required a little more work than the NAD but nothing that wasn’t fixed fairly easily, and Aurender has truly superb after-purchase customer service (as also does NAD). In addition to the built-in storage, the A10 has a 120GB solid-state drive for cache playback. The advantage to this, according to Aurender’s literature, is that by “caching files to the solid-state drive for playback, electrical and acoustic noise resulting from spinning disks, moving heads, and motors is also completely eliminated.” I have no way of assessing whether this is superior to NAD’s buffering system, but it will accept far more material at one time than the M50.2, about 80 CDs worth of files according to John-Paul Lizars, Aurender’s Director of Sales & Marketing. Are the advantages audible in either product? Impossible to tell since there’s no way to circumvent the cache or the buffering. In the year I’ve been using them, both components streamed almost flawlessly, with only the rarest of hiccups or dropouts, and those had to do in almost every instance with Internet issues unrelated to either product.